U.S. Pat. No. 4,117,995, issued Oct. 3, 1978, discloses an aircraft wing lift augmentation device including oval wing leading edge ducts for delivering air diverted from a jet engine or engines over the dorsal wing surface in cooperation with a profiled wing slat and attached air diffusing gridwork which produces laminar flow of air across the top of the wing.
The present invention relates to a fan jet engine bypass air delivery system for use with the blown wing arrangement in the referenced prior patent, although capable of use with other blown wing or wing lift augmentation arrangements.
Among the important objectives of the invention are to utilize relatively cool fan bypass air taken from the annular space surrounding the engine air compressor near the forward end of the engine, thereby eliminating or substantially reducing the amount of titanium structural material in the operational system. The bleeding off of bypass air near the forward end of the compressor also has the advantage of simplifying the positioning of the jet engine in relation to the aircraft wing.
In accordance with the present invention, a positively controlled and guided metallic strip element is normally retracted inside of the exterior engine shell so as not to impede the flow of fan bypass air through the engine. Whenever blown wing activity to augment wing lift is required, the strip element which is flexible is forced into the fan bypass annular space and simultaneously shaped by a series of fixed guides into a concave single convolution spiral diverter, by means of which all of the fan bypass air can be channeled through a common duct to the right and left hand leading edge wing ducts of the wing lift augmentation device in said prior patent.